function logoCentering()
{

	/*

		funkce pro vertikalni vycentrovani obrazku s logem v html konstrukci:

		<h2 id="logo"><a href="./" class="image"><span id="rbcSystemIdentifierLogo"><img src="" alt="" /></span></a></h2>

		nebo

		<h2 id="logo"><span class="image"><span id="rbcSystemIdentifierLogo"><img src="" alt="" /></span></span></h2>

		CSS soubor: #header h2#logo .image { height: 60px; ... }  -> vyska pro obrazek je 60px
		v Safari 3.0.3 pro Win elLogo.offsetHeight vracel namisto 60px vysku obrazku -> proto je do
		vypoctu offsetu "natvrdo" pouzita vyska 60px

	*/

	var rbcLogo = document.getElementById("rbcSystemIdentifierLogo");

	// rodic je tridy "image"
	if ( rbcLogo.parentNode.className == "image" )
	{

		var elImg = rbcLogo.firstChild;

		if (elImg && elImg.offsetHeight == 0)
		{
			Event.observe(window, 'load', function (e)
				{
					setTimeout(logoCentering, 1000);
				}

			);
			return false;
		}

		offsetTop = parseInt(( 60 - elImg.offsetHeight ) / 2 ); // 60 -> Safari bug
		// posouvat obrazek ma cenu pouze pokud je obrazek mensi nez vyska h2#logo
		if ( offsetTop > 0 )
		{
			// posun obrazku o zjisteny offset
			rbcLogo.parentNode.style.overflow = "visible";
			rbcLogo.firstChild.style.position = "relative";
			rbcLogo.firstChild.style.top = offsetTop + "px";
		}
	}
}